QUANTITATIVE MEASUREMENT OF REGIONAL BLOOD-FLOW WITH GADOLINIUM DIETHYLENETRIAMINEPENTAACETATE BOLUS TRACK NMR IMAGING IN CEREBRAL INFARCTSIN RATS - VALIDATION WITH THE IODO[C-14]ANTIPYRINE TECHNIQUE

NMR bolus track measurements were correlated with autoradiographically determined regional cerebral blood flow (rCBF), The NMR method is bas ed on bolus infusion of the contrast agent gadolinium diethylenetriami nepentaacetate and high-speed T-2-sensitive NMR imaging. The first pa ss of the contrast agent through the image plane causes a transient de crease of the signal intensity, This time course of the signal intensi ty is transformed into relative concentrations of the contrast agent i n each pixel, The mean transit time and relative blood flow and volume are calculated from such indicator dilution curves, We investigated w hether this NMR technique correctly expresses the relative rCBF. The r elative blood flow data, calculated from NMR bolus track experiments, and the absolute values of iodo[C-14]antipyrine autoradiography were c ompared. A linear relationship was observed, indicating the proportion ality of the transient NMR signal change with CBF. Excellent interindi vidual reproducibility of calibration constants is observed (r = 0.963 ). For a given NMR protocol, bolus track measurements calibrated with autoradiography after the experiment allow determination of absolute v alues for rCBF and regional blood volume.